Massalia - modern Marseilles - was an important trading centre and the main commercial port in what is now southern France. It was founded circa 600 BC by settlers from Phocaea.

It became the preeminent Greek polis in the Hellenized region of southern Gaul. The city-state sided with the Roman Republic against Carthage during the Second Punic War, retaining its independence and commercial empire throughout the western Mediterranean even as Rome expanded into Western Europe and North Africa.

It lost its independence following the Roman Siege of Massilia in 49 BC, during Caesar's Civil War, in which Massalia sided with the exiled faction at war with Julius Caesar.

It maintained its position as a premier maritime trading hub even after its capture by the Visigoths in the 5th century AD, although the city went into decline following the sack of 739 AD by the forces of Charles Martel.